The present invention belongs to the technical field of image processing for processing image information (image data), and more particularly, to an image processing apparatus capable of appropriately correcting an improper image portion caused on an image on which image data is reproduced, such as a defective image portion caused by flaws of a film, and the like.
Most of the images recorded on photographic films such as negative films and reversal films (which are hereinafter referred to as “films”) are conventionally printed onto light-sensitive materials (photographic paper) by a technique generally called “direct exposure” in which an image on a film is projected onto the light-sensitive material for exposure.
In contrast, recently, a digital photoprinter has been in practical use. The digital photoprinter is arranged such that an image recorded on a film is read photoelectronically and is converted to digital signals, which are subjected to various kinds of image processing steps to produce recording image data, and a light-sensitive material is exposed to recording light beams modulated in accordance with the image data, whereby the light-sensitive material is output as a print on which the image is recorded. Further, the image data is also output to various recording mediums such as a CD-R, and a hard disk (HD) as an image file.
According to the digital photoprinter, the image is read photoelectronically and subjected to image processing steps as digital image data. Thus, in addition to the preferable correction of color and density, an image of high quality can be obtained by performing image processing steps such as gradation correction and sharpness correction which are basically impossible in a printer employing ordinary direct exposure.
Further, it is possible to output not only a print on which the image recorded on the film is reproduced but also a print on which image data (image file) received from a digital camera, and the like (otherwise, from a recording medium which includes the recorded image is reproduced.
Incidentally, there is a defective image portion, which is a serious factor for deteriorating the quality of an image, in an image output from a film acting as an original. The defective image portion is caused by foreign particles such as dust and dirt adhered to the film, a flaw of the film formed by friction, and the like. Further, in the images recorded by the digital camera, and the like, a similar defective image portion may be caused by so-called defective pixels such as the defects of CCD cells.
Conventional printers employing the direct exposure output a print by correcting the defective image portion in such a manner that an operator manually cleans a film or corrects an image (film) with a color material.
Whereas, in the digital photoprinters that photoelectrically read the images on a film or receive image data from digital cameras, and the like and process the image data as digital image data, it is possible to detect a defective image portion by analyzing the digital image data and to correct it by executing the image processing steps.
For example, JP 6-28468 A, JP 11-75039 A, JP 2001-24883 A, JP 2001-24884 A and JP 2001-24895 A each disclose an image processing apparatus for correcting a defective image portion caused by a foreign particle and a flaw making use of infrared light (IR) beams, which are not absorbed by the images recorded on a film but are shaded, absorbed and scattered by the foreign particle, the flaw, and the like. That is, in this image processing apparatus, when an image recorded on a film is photoelectrically read by a CCD sensor, and the like, in addition to the reading of a visible image through three R (red), G (blue), and B (blue) primary colors, the film is read with infrared light beams so as to detect the foreign particle and the flaw by the change of intensity of the infrared light beams.
In the image processing disclosed in the above publications or other image processing for correcting a defective image portion caused on an image on which image data is reproduced as a visible image (or on an image carried by the image data), the defective image portion is corrected by an image processing step such as interpolation of the image data after the defective image portion has been detected.
However, in the above image processing step, a portion where no image is defective may be detected as a defective image portion depending upon a picture, and the like and a defective image portion may not be always appropriately corrected depending on a size of the defective image portion and on a picture located at a position where a defective image portion exists. In this case, an improper image is output as a matter of course.